Thermostatic regulating or controlling apparatus



l A.. H.. McNEII.. THERMOSTATI'C REGULATING OFI CONTROLLING IIARTUS.

y APPLICATION FILED IML-23. 1918- Patented May 23, 1922.

2 mens-suur 1.

-A. H. McNEIL.

THERMOSTATIC REGULATING 0R CONTROLLING APPARATUS.

APPLICATION FILED IMI. 23, 1918.

Patented May 23, 1922.

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UNITED STATES lPATENT OFFICE.

ALFRED HENRY rreiinrnor enmarcan, ENGLAND.

THERMOSTATIC REGULATNG- OR CONTR-OLLING APPARATUS.`

Specification of Letters Patent. Pattgd 'Biggy 23, "1922.

Application Ied January 23, 1918. Serial No. 213,326.

Manatoin Victoria `Roa-d, Chingford, Es-

ser, England, here invented certain new and useful improvements inThermostatic Regulating or Controlling- Apparatus, of

`which the followino is a s eciiication.

This invention relates to thermostatic regulating or controllingapparatus and has for its object to provide an improved apparatuscapable of controlling fairly high temperatures ranging for example upto 1,000O F., such apparatus being applicable Tor a variety of usesincluding; the control of electrically heated induction pipes. ofengines employed on aircraft, muilles or inutile fur-` naces and variouselectric, gas, hot water and other heatingl systems and apparatus.

The invention comprises an elongated thermo-sensitive member or tubefixed at one end and supporting by its other or free end a secondelongated member to which longif tudinal movement is imparted due to theeffects of changes of temperature on the elongated siuiporting member.such move-- ment being transmitted to an electric contact, valve, orother controlling` device. The invention also comprises electricalcontrol.- ling means. l

According` to this invention a thermosensitive member consisting` of atube or sleeve made of metal having a high co-e'ilicient of expansion isxed at one end and free atthe other end, anda rod or tube made oi metalor other material havinga lower co-eiiicient oi expansion is fixed atone end to the free end of thc metal tube and extends freely within theAtube in the direction of vthe liired end of the said tube where itoperates on a movable electric contact, valve or other device.

electrical system of control co-operating with the thermo-sensitivedevice and designed to open and close a switch in the circuit of anelectrical heating apparatus, includes a pivoted switch arm withcontrolling coil or relay, a pivoted locking arm for'the switch varmalso with controlling coil, and electrical circuits controlled by amovable contact co-operating with two fixed contacts for energizingand(ie-energizing the coils. y

The switch is closed by the action of its coil upon the closing of. acircuit by the movable ycontact operated bythe thermosensitive member,and automatically locked in the closed position by the locking arm, thesaid switch 'being released and moved into the op'enposition under theaction ot a spring by the closing of another circuit by the same contactmember which is moved from the switch closing contact to a switchopening contact under the action of the thermo-sensitive device as thetemperature rises.

In orderto prevent sparking the con-y trolling' circuits of both theswitch arm and switch locking arm are broken automatically as soon astheir coils have operated the said arms, by carbon contacts carried onand tact carried on the switch arm operating in the circuit of thelocking rarm and the contact on the locking arm operating in the circuitof the switch arm, the locking arm being held up in the in-operativerposition by the switch arm, and moved into the locking position by aspring or other means when the switch is closed. Other means ofcontrollingP the opening; and closing oit' the heating circuit by thethermo-sensitive device may be adopted. fin the case of gas heatedapparatus the movable member of the thermostat may operate directly upona valve for turning on or shutting off the supply.

Then the invention is applied to the induction ipe of an aircraft engineheated electrical y the pipe is provided with a chambered cap having-"aremovable cover.

` lVithin the chamber is mounted a blade car- `moving with the armsthemselves, the conrying an adjustable screw with pointer movi Vableovera dial and a movable contact arranged eccentrically of the screw andcooperating` with a fixed contact in the controlling circuit. l

In vthe accomp anying drawings z* Fig. l is a longitudinal sectionthrough an induction pipe fitted with a thermostatic device constructedaccording to the invention and also shown in section,

I Fie. 2 is a plan of the same with the cover removed,

And Figs. 3 and 4 are diagrams of electrical systems of controlco-operating with the thermo-sensitive member.

Referring first to Figs. 1 and 2 which` `clearly illustrate the`thermostatic contact making or breaking device, a tube e of brass orother metal with a high co-efiicientl of vexpansion is iXed at one endonly anden-

